Method for producing polymer tube containing liquid and being sealed at constant intervals and apparatus for producing polymer tube

ABSTRACT

Provided are a method and an apparatus for extruding into a tube and filling the tube at a high speed and simultaneously sealing the tube. Specifically provided is a method for producing a polymer tube, containing a liquid therein and being sealed at constant intervals, the method including an extrusion step of continuously melt-extruding a polymer material through a die into at least one tube, while feeding a liquid into the tube to obtain at least one liquid-containing tube; and sealing step of discontinuously pressing the at least one liquid-containing tube between a pair of pressurizing members at constant intervals to cause pressure-bonding before the tube solidifies, while continuously taking up the extruded tube.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to a method for producing a polymer tube sealedand containing a liquid substance such as a pheromone, a flavoringagent, an insect repellent and an insecticide in a form liquid orsolution, and to an apparatus for producing a polymer tube.

2. Related Art

There is a conventional packing method for filling a polymer tube with afluid substance, a jelly-like substance, or the like. The conventionalmethod comprises steps of: sealing a long tube at one end, feeding asubstance into the tube from the other end, and sealing and cutting thetube at a certain length. In the method, such a long polymer tube cannotbe produced so that it is necessary to feed the substance into eachtube, preventing continuous packing.

When an inner diameter of a tube is required to be controlled, JP7-148812A discloses a method for continuously producing a polymer tube,comprising a step of controlling the inner diameter by a mandrelprotruding forward from an extruder, while cooling the tube forsolidification from the inner surface by using a substance to be fed asa refrigerant. The tube into which the substance is fed is taken up andthen sealed and cut with a seal cutter. JP 49-38789A discloses a methodfor producing a sustained-release preparation having an inner diameterof 0.4 to 4 mm, comprising steps of extruding a melted polymer material,while injecting a volatile substance in a form of liquid. Also in themethod, an extruded tube is heat-sealed and cut at a certain length.

SUMMARY OF THE INVENTION

A polymer tube containing a substance in a form of liquid or fluidtherein is conventionally sealed by the method comprising steps of:extruding a polymer material into a tube; solidifying the tube to fixthe inner diameter or the wall thickness of the tube; and melting thetube again for heat-sealing, ultrasonic sealing, or the like. Suchsealing requires time for preheating, pressure-bonding, and coolingafter retention of pressure-bonding. Hence, the speed of taking up theextruded tube has to be limited in order to allow the tube to becontinuously extruded and sealed. For this reason, when a polymer tubeis taken up at a high speed, the sealing has to be done in a separatestep or line.

In such circumstances, the invention is made to provide a method forproducing a polymer tube, in which a polymer tube is extruded and filledwith a liquid substance at a high speed, and simultaneously sealed; andan apparatus for producing the polymer tube.

In an aspect of the invention, there is provided a method for producinga polymer tube, containing a liquid therein and being sealed at constantintervals, the method comprising: an extrusion step of continuouslymelt-extruding a polymer material through a die into at least one tube,while feeding a liquid into the at least one tube to obtain at least oneliquid-containing tube; and a sealing step of discontinuously pressingthe at least one liquid-containing tube between a pair of pressurizingmembers at constant intervals to cause pressure-bonding before the tubesolidifies, while continuously taking up the extruded tube.

In another aspect of the invention, there is provided an apparatus forproducing a polymer tube, containing a liquid therein and being sealedat constant intervals, the apparatus comprising: a die configured formelt extrusion of a polymer material into at least one tube; a mandrelconfigured to feed a liquid into the at least one tube during the meltextrusion to obtain at least one liquid-containing tube; one or morerollers configured to take up the at least one liquid-containing tube;and a pair of pressurizing members configured to discontinuously pressthe at least one liquid-containing tube between the pair of pressurizingmembers to cause pressure-bonding before the tube solidifies.

According to the invention, a polymer tube containing a liquid thereinand being sealed at constant intervals is produced by extrusion of apolymer material into a tube, feeding of the liquid into the tube andsealing, while maintaining a speed of taking up the extruded tube.Hence, it is not necessary to provide a sealing device separately sothat the steps are carried out in a simpler manner and in a shorterperiod of time.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top cross-sectional view of an embodiment of apparatus forproducing a polymer tube containing a liquid substance therein andsealed at constant intervals.

FIG. 2A shows the clearance C between a pair of rotary horns, and FIG.2B shows that the clearance C is the same as the thickness of a sealedpart of a polymer tube.

FIG. 3 is a top cross-sectional view of an embodiment of apparatus forproducing two horizontally aligned polymer tubes, pressed in thehorizontal direction for sealing and thereby simultaneously connectedeach other at constant intervals, each polymer tube containing a liquidsubstance therein.

FIG. 4 shows discharge ports of a die in the apparatus in FIG. 3.

FIG. 5 shows an embodiment of vertical sealing by using guides which arepositioned above and below one of the protrusions of a pair of rotaryhorns and which are protruding more than the protrusion.

FIG. 6 shows two polymer tubes connected at a sealed part, produced bypressing the two horizontally aligned polymer tubes in the horizontaldirection with the apparatus in FIG. 3.

FIG. 7 is a side cross-sectional view of an embodiment of apparatus forproducing two vertically aligned polymer tubes with an interconnectingweb therebetween, being pressed in the horizontal direction for sealingat constant intervals and each polymer tube containing a liquidsubstance therein.

FIG. 8 shows discharge ports of a die in the apparatus in FIG. 7.

FIG. 9 shows an example of horizontal sealing in which one of a pair ofrotary horns has a blade which protrudes radially higher than theprotrusion on circumference.

FIG. 10 shows an embodiment in which one of the rotary horns has a bladewhich protrudes radially higher than the protrusion on thecircumference, and the other of the rotary horns has a blade receiverhaving a groove, the blade receiver protruding radially higher than theprotrusion on the circumference and receiving the blade in the groove.

FIG. 11 shows two polymer tubes with an interconnecting webtherebetween, produced by pressing the two vertically aligned polymertubes in the horizontal direction with the apparatus in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A method for producing a polymer tube, containing a liquid substancetherein and sealed at constant intervals, comprises an extrusion step ofcontinuously melt-extruding a polymer material through a die into atleast one tube, while feeding a liquid substance into the at least onetube to obtain at least one liquid substance-containing polymer tube;and a sealing step of discontinuously pressing the at least one liquidsubstance-containing tube between a pair of pressurizing members atconstant intervals to cause pressure-bonding before the polymer tubesolidifies, while continuously taking up the extruded polymer tube.

A polymer tube is molded by extruding a melted polymer material througha die into a tube. A conduit is preferably inserted into a pore of amandrel placed in the die, and the leading end thereof is placed near adischarge port of the die for discharging a melted polymer material. Aliquid substance is discharged from the conduit.

Although a single polymer tube may be extruded from a die, two or morepolymer tubes may be simultaneously extruded. Of two or more polymertubes, at least one tube may be filled with a liquid substance. Examplesof the two or more polymer tubes may include a combination of tubes, ora combination of at least one tube and at least one rod. Of two or morepolymer tubes, at least two may be connected by a web. The web is, forexample, a continuous connecter interconnecting a tube and a tube, atube and a rod, or a rod and a rod in a longitudinal direction.

When a die comprises a cross-section having two pores, two polymer tubesare obtained in the extrusion step, and two polymer tubes sealed andthereby simultaneously connected at constant intervals, each tubecontaining a liquid substance, are obtained in the sealing step.

When a die comprises a cross-section having two pores and a slitcommunicating with the two pores, two polymer tubes connected by a webare obtained in the extrusion step, and two polymer tubes sealed atconstant intervals and connected by a web are obtained in the sealingstep.

When a die comprises a cross-section having two pores and a slitcommunicating with the two pores, and one of the rotary horns has ablade which protrudes radially higher than the protrusion on thecircumference, two polymer tubes connected by a web are obtained in theextrusion step, and the polymer tubes are not only pressure-bondedbetween protrusions of the rotary horns but also notched in the web bythe blade along the longitudinal direction except the pressure-bondedparts in the sealing step. Consequently, two polymer tubes sealed atconstant intervals and connected by a notched web, each containing aliquid substance, can be produced.

A polymer tube for storing a liquid substance can be produced bycontinuous extrusion molding using a polymer material. The innerdiameter of the polymer tube may be selected depending on requiredcharacteristics of an end product, and may be variable with the numberof extruded tubes. It is preferably 0.4 to 2 mm, more preferably 0.6 to1.6 mm from the standpoint of moldability or the feeding property of aliquid substance. By selecting the sealing intervals depending on theinner diameter of a polymer tube, an amount of a liquid substancecontained in a polymer tube sealed at both ends, which are obtained bycutting at sealed parts, may be controlled.

The polymer tube preferably has a wall thickness of 0.2 to 1.5 mm, morepreferably 0.25 to 0.8 mm from the standpoint of moldability, thediffusion speed of the liquid substance, or economy.

When two or more polymer tubes are obtained by extrusion, the gapbetween the polymer tubes may be selected by preferably adjusting theminimum distance between the outer peripheries of pores in a die to arange of 0.5 to 5 mm. When polymer tubes are connected by a web, thewidth of the web connecting the polymer tubes is selected by preferablyadjusting the width of a slit in a die (wherein the width is the minimumdistance between the outer peripheries of pores in a die) to a range of0.5 to 5 mm and preferably adjusting the thickness of the slit (whereinthe thickness is perpendicular to the width) to a range of 0.1 to 0.5mm.

The processing temperature during the molding of a polymer material istypically about 80 to 300° C., which may vary with the type of a polymermaterial. For example, when a high-density polyethylene is selected asthe polymer material, the extruder is preferably set at 180 to 250° C.,and the die is preferably set at 250° C. When an ethylene-vinyl acetatecopolymer is selected as the polymer material, the extruder ispreferably set at 130 to 170° C., and the die is preferably set at 170°C. When an aliphatic polyester is selected as the polymer material, theextruder is preferably set at 70 to 130° C., and the die is preferablyset at 130° C.

As described above, the processing temperature depends on the type of apolymer material. An optimum temperature at which a polymer material canbe extruded uniformly may be selected to obtain an intended tube.

The take-up speed of the polymer tube is preferably controlled at aconstant value. When the amount of a polymer material extruded from anextruder and the inner diameter of a tube are constant, the wallthickness of the tube may be appropriately controlled by changing thetake-up speed of the polymer tube.

The take-up speed of the polymer tube varies with the extruderperformance, a shape of the tube, or physical properties of the polymermaterial. It is preferably 20 to 300 m/min, more preferably 40 to 200m/min. When the take-up speed is less than 20 m/min, the productivitymay be lowed. When the take-up speed is more than 300 m/min, an amountof the polymer material extruded per unit time becomes large so that alarge extruder or a device for after-treatment including winding of thepolymer tube may be needed, or the polymer tube may lack dimensionalstability.

A pair of pressurizing members discontinuously press a polymer tubebeing taken up to cause pressure-bonding at constant time intervalsbefore the polymer tube is cooled and solidified. As a result, thepolymer tube is sealed. The pair of pressurizing members may be anypressurizing members which can discontinuously pressure-bond a polymertube from both sides. For example, each pressurizing member comes closerto a polymer tube from the corresponding side in a directionperpendicular to the take-up direction at intended time intervals, theninstantaneously pressure-bonds the polymer tube, and gets away. Such acycle can be repeated. In order not to change the take-up speed when apressure is applied, each pressurizing member preferably may comprise afreely rotatable part (e.g. head) which comes into contact with thepolymer tube during application of pressure. Each pressurizing member ispreferably a member made from a metal such as iron, aluminum, andstainless steel; a hard rubber; or a plastic such as a rigid plastic.

A pair of pressurizing members is preferably a pair of rotary horns,each having a protrusion. A polymer tube is allowed to pass between thepair of rotary horns, and the protrusions discontinuously pressure-bondthe polymer tube for sealing. Preferably, the pair of rotary hornsrotates at the same peripheral speed as the take-up speed so as totransfer the polymer tube in the take-up direction.

The material of the rotary horn may be any material having a higherhardness than that of a melted polymer material, and more preferably ametal such as iron, aluminum and stainless steel; a hard rubber; or aplastic such as a rigid plastic is used.

As for the shape of the protrusion for sealing, a dimension of a flatpart on the leading end substantially corresponds to a sealing width ofa polymer tube. The sealing width is suitably about 4 to 15 mm. It isimportant not to allow a liquid substance to leak from the sealed partwhen the sealed part is cut in the middle thereof. When an edge of theprotrusion sharply comes into contact with a polymer tube, the wall ofthe polymer tube is drawn into a thin wall, which may cause the leakageof a liquid substance. Hence, the edge of the protrusion is preferablychamfered into an R-shape. The R-shape preferably has a radius of 0.1 to1 mm, which may vary with the width of a flat portion.

Each rotary horn excluding the protrusion may be of any shape whichallows it to come into contact with neither a polymer tube nor a sealedpolymer tube except that the blade is allowed to come into contact witha web. Examples of the shape include a cylinder (including a disc) and aquadrangular prism. The cylinder is more preferable.

A polymer tube is pressure-bonded between the protrusions of the pair ofrotary horns. However, when two protrusions come in contact with eachother, the tube is cut. Accordingly, the rotary horns may preferablyhave a clearance of 0.3 to 1.0 mm so that the tube can be flattened,while leaving a certain thickness.

A pair of rotary horns preferably rotates at the peripheral speed equalto the take-up speed. A pair of rotary horns preferably rotates in sucha manner that a polymer tube is moved in the same direction as thetake-up direction. Hence, the rotary horns rotate in oppositedirections, and the direction in which each protrusion comes closer forpressure bonding and gets away after pressure-bonding, is the samedirection as the take-up direction. The peripheral speed is the same asthe take-up speed. This suppresses an influence on the take-up speed ofa polymer tube before, during and after sealing, and enables the sealingwith a pair of rotary horns.

When the peripheral speed of rotary horns is the same as the take-upspeed, the circumference formed by the radius of the rotary hornincluding the protrusion is equal to the sum of each length of constantintervals for sealing a polymer tube containing a liquid substancetherein and the length of a sealed part. For example, to obtain apolymer tube sealed at each pitch of 200 mm, cylindrical rotary hornshaving a radius (including a protrusion) of 31.85 mm can be used.Alternatively, by setting an idle period of the rotation cycle of therotary horn, an intended interval can be selected. For example, toobtain a polymer tube sealed at each pitch of 400 mm, cylindrical rotaryhorns having a radius (including a protrusion) of 31.85 mm can be usedto repeat a cycle in which the rotary horns are stopped for a time ofone revolution and then are rotated for one revolution.

To allow the rotary horns to rotate at the same speed as the take-upspeed, for example, the speed of a rotary motor for the take-up rolleris measured, and then an electric signal is sent to a rotary motorcontroller of the rotary horns. For example, when a change in voltage orthe like causes a change in the rotation speed of a rotary motor for thetake-up roller, the peripheral speed of the rotary horns can becontrolled. As a result, the sealing can be done at constant sealpitches.

A long polymer tube after extruded from a die and before cooled andsolidified is flattened and sealed by pressurizing members such as bothprotrusions of a pair of rotary horns. A polymer tube is preferablyallowed to pass through a cooling bath such as a water bath to be cooledand solidified to obtain a sealed polymer tube. An extruded polymer tubemay be sealed before introduction into the cooling bath. Alternatively,a polymer tube just after the extrusion may be sealed in the coolingbath in which a pair of rotary horns is placed. It is preferable to seala polymer tube when the outer surface layer of a polymer tube starts tosolidify, but the inner wall surface is still in a molten state. Thetemperature of the cooling bath for sealing (first cooling bath) may beany temperature at which the outer surface is solidified, and ispreferably 20 to 60° C., more preferably 25 to 40° C. The sealed polymertube is completely solidified in a subsequent cooling bath (secondcooling bath) at a temperature 10 to 30° C. lower than that of the firstcooling bath. It is preferable to use two or more cooling baths.However, it is possible to use only a single cooling bath whichpreferably has a temperature of 15 to 60° C.

When two polymer tubes has an interconnecting web, the web of thepolymer tubes or the web of the polymer tubes cut at the middle ofsealed parts is preferably notched at the middle of the web in alongitudinal direction by using a cutting device such as a cutter. Bytearing the notch, the resulting polymer tubes can be placed through atree branch or the like. When one of the rotary horns has a blade whichprotrudes radially except at a location of the protrusion and whichprotrudes more than the protrusion, it can flatten the extruded tubestogether with the other of the rotary horns and can notch the web in alongitudinal direction. The other of rotary horns preferably has a bladereceiver with a groove wherein the receiver is formed circumferentiallyexcept at a location of the protrusion. Such a structure allows theblade to be inserted into a groove, while a web is notched. Accordingly,predetermined positions on the web can be notched without displacement.The blade and the blade receiver with a groove are preferably providedon the periphery of each rotary horn except at a location of eachprotrusion in such a manner as to form a gap having a length of from 5mm to ¼ of the outer periphery of each rotary horn (including eachprotrusion) at each side of the protrusion. Specifically, the materialof the blade receiver with a groove is preferably a heat resistant resinsuch as polyamide and polytetrafluoroethylene.

The polymer tube is cut preferably perpendicularly to the longitudinaldirection at the sealed parts formed by flattening with pressurizingmembers of a pair of rotary horns or the like, preferably at the middleof each sealed part in a longitudinal direction to obtain short polymertubes sealed at both ends, each sealed tube containing a liquidsubstance such as a pheromone therein. The cutting device is notspecifically limited, and a cutter such as a knife may be used.

The amount of the liquid substance contained in a polymer tube sealed atboth ends may be any amount, and may be selected depending on requiredcharacteristics of an end product. As an example, a sustained-releasepreparation for disrupting mating will be described. For example, eachpolymer tube sealed at both ends and containing a sex pheromone thereinis placed in a field, and the sex pheromone is gradually released tomake the whole field in a sex pheromone atmosphere. Thus, intendedinsect pests are prevented from mating, thereby lowering the populationdensity of the next generation.

It is considered that as the number of sustained-release preparationsplaced in a field is larger, the pheromone concentration can become moreuniform in the whole field. In consideration of the time and effort forthe placement, the placement of 20 to 5,000 preparations per hectare isthought to be a preferable allowable range. The amount of a pheromonerequired for mating disruption naturally varies with the populationdensity and sensitivity of intended insect pests. It is typically andpreferably 0.1 to 10 g/day/hectare of a pheromone. As for the period forthe release of a pheromone, a pheromone atmosphere is required to bemaintained during the period that intended insect pests are adults. Theadult period varies with intended insect pests, and the number ofrepeating times of the adult period also varies with insect pests.Typically, the release is required for 1 to 10 months. In considerationof these situations, 20 mg to 50 g of a pheromone is required to becontained in a polymer tube sealed at both ends.

An apparatus for producing a polymer tube, containing a liquid substancesuch as a pheromone therein and being sealed at constant intervals,comprises a die configured for melt extrusion of a polymer material intoat least one polymer tube; a mandrel configured to feed a liquidsubstance into the at least one polymer tube during the melt extrusionto obtain at least one liquid-substance-containing polymer tube; one ormore take-up rollers configured to take up the at least oneliquid-substance-containing polymer tube; and a pair of pressurizingmembers configured to discontinuously press the at least oneliquid-substance-containing polymer tube between the pair ofpressurizing members to cause pressure-bonding before the polymer tubesolidifies.

A pair of pressurizing members is preferably a pair of rotary horns eachhaving a protrusion, and the pair of the rotary horns discontinuouslypressure-bonds the taken-up polymer tube between the protrusions to sealthe polymer tube.

FIG. 1 shows a top cross-sectional view of an embodiment of apparatusfor producing a polymer tube containing a liquid substance therein andsealed at constant intervals. The apparatus comprises a die 12 for meltextrusion of a polymer material P introduced into an extruder 11, into atube through a discharge port 16 to obtain a polymer tube; a mandrel 13for feeding a liquid substance L into the tube during the extrusion;take-up rollers 19 for taking up the extruded polymer tube; and a pairof rotary horns 17, 18 for discontinuously pressure-bonding the taken-uppolymer tube between protrusions 17 a, 18 a for sealing before thepolymer tube solidifies. In the mandrel 13, a conduit 14 for supplyingthe liquid substance L is provided, and the conduit 14 comprises anopening and closing valve 15 for controlling the amount of the liquidsubstance L to be supplied. A pair of rotary horns 17, 18 and thetake-up rollers 19 are driven by corresponding motors 20, 21, which arecontrolled by a control board 22. The polymer tube that has beendiscontinuously flattened and sealed by the protrusions 17 a, 18 a iscooled in a cooling bath 23 such as a water bath.

FIG. 2A shows the clearance C between a pair of rotary horns, and FIG.2B shows that the clearance C is the same as the thickness of a sealedpart of a polymer tube. If the leading ends of protrusions, eachprotrusion having a radius R, come into contact with each other, then apolymer tube is cut. Hence, the rotary horns are preferably selected tomake a clearance C of 0.3 to 1.0 mm to prevent the leading ends fromcoming into contact with each other.

FIG. 3 shows a top cross-sectional view of an embodiment of apparatusfor producing two horizontally aligned polymer tubes, pressed in thehorizontal direction for sealing and thereby simultaneously connectedeach other at constant intervals, each polymer tube containing a liquidsubstance therein. The apparatus comprises a die 32 for melt extrusionof a polymer material P introduced into an extruder 31, into a tubethrough discharge ports 36 a, 36 b to obtain two polymer tubes; mandrels33 a, 33 b for feeding a liquid substance L into the tubes during theextrusion; take-up rollers 39 for take-up the extruded polymer tubes;and a pair of rotary horns 37, 38 for discontinuously pressure-bondingthe taken-up polymer tubes between protrusions 37 a, 38 a for seal andconnection before the polymer tubes solidify. In the mandrels 33 a, 33b, conduits 34 a, 34 b for supplying the liquid substance L areprovided, and the conduits 34 a, 34 b comprise opening and closingvalves 35 a, 35 b for controlling the amount of the liquid substance Lto be supplied. A pair of rotary horns 37, 38 and the take-up rollers 39are driven by corresponding motors 40, 41, which are controlled by acontrol board 42. The rotary horns 37, 38 are placed in a cooling bath43 a such as a water bath, and the polymer tubes discontinuouslyflattened for seal and connection are cooled in a cooling bath 43 b suchas a water bath.

FIG. 4 shows the discharge ports 36 a, 36 b of the die 32 in theapparatus in FIG. 3. The discharge ports 36 a, 36 b discharge not onlythe polymer material P but also the liquid substance L supplied from theconduits 34 a, 34 b.

FIG. 5 shows an embodiment of vertical sealing by using guides which arepositioned above and below one of the protrusions of a pair of rotaryhorns and which protrude more than the protrusion. The sealing is calleda vertical type because a sealed part extends vertically to the plane ofpolymer tubes arranged horizontally and in parallel. The pair of rotaryhorns 37, 38 discontinuously pressure-bond the taken-up polymer tubesbetween protrusions 37 a, 38 a for seal and connection before thepolymer tubes solidify.

To prevent a liquid substance from leaking, two polymer tubes areideally pressure-bonded vertically to the central axes of the twopolymer tubes for sealing within the outer diameters of the two polymertubes. To prevent the displacement of two polymer tubes for the abovesealing, optional guides for supporting the two polymer tubes extrudedmay be provided around one of the protrusions of a pair of rotary horns.FIG. 5 shows a pair of guides 44, 45 positioned above and below theprotrusion 38 a of one of the rotary horns. The material of the guidesmay be any material which can prevent the displacement of polymer tubes,and more specifically, it is preferably a heat resistant resin such aspolyamide and polytetrafluoroethylene.

The distance between the pair of guides may be changed depending of theouter diameter of a polymer tube, and is preferably the same as theouter diameter of a polymer tube.

FIG. 6 shows two polymer tubes connected at a sealed part at which thetwo polymer tubes are pressure-bonded in the horizontal direction, andwhich is produced with the apparatus in FIG. 3.

FIG. 7 shows a side cross-sectional view of an embodiment of apparatusfor producing two vertically aligned polymer tubes with aninterconnecting web therebetween, being pressed in the horizontaldirection for seal at constant intervals and each polymer tubecontaining a liquid substance therein. The apparatus comprises a die 72for melt extrusion of a polymer material introduced into an extruder,into a tube through discharge ports 76 a, 76 b to obtain two polymertubes connected by a web; mandrels 73 a, 73 b for feeding a liquidsubstance L into the tubes during the extrusion; take-up rollers 79 fortaking up the extruded polymer tubes; and a pair of rotary horns 77 (notshown), 78 for discontinuously pressure-bonding the taken-up polymertubes between protrusions (not shown) before the polymer tubes solidify.In the mandrels 73 a, 73 b, conduits 74 a, 74 b for supplying the liquidsubstance L are provided, and the conduits 74 a, 74 b comprise openingand closing valves 75 a, 75 b for controlling the amount of the liquidsubstance L to be supplied. A pair of rotary horns 77 (not shown), 78and the take-up rollers 79 are driven by corresponding motors 80, 81,which are controlled by a control board 82. The rotary horns 77 (notshown), 78 are placed in a cooling bath 83 a such as a water bath, andthe polymer tubes that have been discontinuously flattened and sealedare cooled in a cooling bath 83 b such as a water bath.

FIG. 8 shows the discharge ports 76 a, 76 b of the die 72 in theapparatus in FIG. 7. The discharge ports 76 discharge not only thepolymer material P but also the liquid substance L supplied from theconduits 74 a, 74 b.

FIG. 9 and FIG. 10 show an embodiment in which one of a pair of rotaryhorns has a blade which protrudes radially higher than the protrusion onthe circumference. The pair of rotary horns 77, 78 discontinuouslypressure-bond the taken-up polymer tubes between protrusions 77 a, 78 afor seal before the polymer tubes solidify. The rotary horn 77 has ablade 77 b which protrudes radially except at a location of theprotrusion 77 a and which protrudes more than the protrusion 77 a. Theblade 77 b can form a notch S in a web in a longitudinal direction.

When one of the rotary horns has a blade which protrudes radially higherthan the protrusion on the circumference, the other of the rotary hornsmay have a blade receiver having a groove, the blade receiver protrudingradially higher than the protrusion on the circumference, and the groovereceiving the blade. In FIGS. 9 and 10, the rotary horn 78 has a bladereceiver with a groove for storing the blade 77 b. However, one of therotary horns 77, 78 may have a blade, while the other of the rotaryhorns 77, 78 may have a blade receiver with a groove.

The distance between the protrusion and the blade in the circumferentialdirection with respect to a rotary horn having a blade, and the distancebetween the protrusion and the blade receiver with a groove in thecircumferential direction with respect to a rotary horn having a bladereceiver with a groove, for example, d1, d2 in FIG. 10, are not limitedto particular values, and are preferably 3 to 7 mm, more preferablyabout 5 min.

FIG. 11 shows two polymer tubes with an interconnecting webtherebetween, produced by pressing the two vertically aligned polymertubes in the horizontal direction with the apparatus in FIG. 7.

Examples of the polymer material include thermoplastics such aslow-density polyethylene, high-density polyethylene, polypropylene, anethylene-propylene copolymer, an ethylene-vinyl acetate copolymer, anethylene-acrylic ester copolymer, polyvinyl acetate, a polyvinylchlorideresin, polystyrene, a polyimide resin, polycarbonate, polyvinylidenechloride, polybutylene, a methyl methacrylate-styrene copolymer,polyacetal, cellulose acetate, cellulose-acetate butyrate,polyvinylidene fluoride, and a silicon resin. Other examples includecondensation polymers of at least one dicarboxylic acid selected fromthe group consisting of oxalic acid, malonic acid, succinic acid,glutaric acid, adipic acid, sebacic acid, fumaric acid and maleic acidwith at least one polyol selected from the group consisting of ethyleneglycol, propylene glycol, butanediol, pentanediol, hexanediol,octanediol and decanediol. In addition, a condensation polymer of atleast one selected from the group consisting of lactic acid,hydroxyvaleric acid, hydroxycaproic acid and hydroxy capric acid; or athermoplastic including an aliphatic polyester of polycaprolactone maybe used.

Specifically, when the polymer tube is used as a sustained-releasepreparation, the polymer material is appropriately selected depending ona substance to be fed. When the liquid substance is a pheromone or thelike, a polyolefin such as polyethylene and polypropylene, or anethylene-vinyl acetate copolymer is preferred in consideration ofcompatibility or membrane permeability.

Such a polymer material may contain a lubricant, a plasticizer, astabilizer, a pigment, or a filler.

A liquid substance having a boiling point of 170° C. or more may beused. The temperature during extrusion is typically about 80 to 300° C.so that a liquid substance having a boiling point of less than 170° C.may partially vaporize during injection, thereby making the injectionamount unstable. More specifically, for example, a pheromone, arepellent, a flavoring agent, an insect repellent, or a deodorant may beused. In particular, the pheromone includes many high-molecular-weightliquid substances having 10 or more carbon atoms and has comparativelylow viscosity, so that it is suitable when the polymer tube is used as asustained-release preparation. The liquid substance to be containedpreferably has a viscosity of 10 mPa·s or less at an ambienttemperature, or it may be substance which becomes a low viscosity byheating. The pheromone may be an extract from insects or the like, butit is preferably an artificially synthesized pheromone from theviewpoint of mass production.

Examples of the pheromone include a linear aliphatic aldehyde having 12to 20 carbon atoms, a linear aliphatic acetate being saturated or havingat least one double bond and having 12 to 20 carbon atoms, a linearaliphatic alcohol having 7 to 20 carbon atoms, a spiroacetal having 7 to15 carbon atoms, a linear aliphatic ketone having 10 to 25 carbon atoms,an aliphatic hydrocarbon having 10 to 30 carbon atoms, and a carboxylicacid having 10 to 20 carbon atoms. In particular, the linear aliphaticaldehyde having 12 to 20 carbon atoms, the linear aliphatic acetatebeing saturated or having at least one double bond and having 12 to 20carbon atoms, the linear aliphatic alcohol having 7 to 20 carbon atoms,or the spiroacetal having 7 to 15 carbon atoms are preferable. Specificexamples include Z7Z11-hexadecadienyl acetate and Z7E11-hexadecadienylacetate as sex pheromones of the pink bollworm (Pectinophoragossypiella), Z-8-dodecenyl acetate as a sex pheromone of the Orientalfruit moth (Grapholita molesta), E-5-decenyl acetate as a sex pheromoneof the peach twig borer (Anarsia lineatella), Z-9-dodecenyl acetate as asex pheromone of the grape berry moth (Eupoecilia ambiguella),E7Z9-dodecadienyl acetate as a sex pheromone of the European grape vinemoth (Lobesia botrana), E-11-tetradecenyl acetate as a sex pheromone ofthe light brown apple moth (Epiphyas postvittana), E8E10-dodecadienol asa sex pheromone of the codling moth (Cydia pomonella), Z-11-tetradecenylacetate as a sex pheromone of the leaf roller (Tortricidae),Z3Z13-octadecadienyl acetate and E3Z13-octadecadienyl acetate as sexpheromones of the peach tree borer (Synanthedon exitiosa),Z-11-hexadecenal as a sex pheromone of the American bollworm(Helicoverpa armigera), Z-9-hexadecenal as a sex pheromone of theoriental tobacco bud worm (Heliothis assulta), E8E10-dodecadienylacetate as a sex pheromone of the soybean pod borer (Leguminivoraglycinivorella), Z-11-hexadecenyl acetate and Z-11-hexadecenal as sexpheromones of the diamondback moth (Plutella xylostella),Z-11-hexadecenyl acetate, Z-11-hexadecenol and n-hexadecyl acetate assex pheromones of the cabbage armyworm (Mamestra brassicae),Z9E12-tetradecadienyl acetate and Z-9-tetradecenol as sex pheromones ofthe beat armyworm (Spodoptera exigua), Z9E11-tetradecadienyl acetate andZ9E12-tetradecadienyl acetate as sex pheromones of the common cutworm(Spodoptera litura), Z-9-tetradecenyl acetate as a sex pheromone of thefall armyworm, E-4-tridecenyl acetate as a sex pheromone of the tomatopinworm, Z-11-hexadecenal and Z-13-octadecenal as sex pheromones of therice stem borer (Scirpophaga incertulas), 5,9-dimethylpentadecane and5,9-dimethylhexadecane as sex pheromones of the coffee leaf miner,14-methyl-1-octadecene as a sex pheromone of the peach leaf miner(Lyonetia clerkella L.), Z-13-icosen-10-one as a sex pheromone of thepeach fruit moth (Carposina sasakii), 7,8-epoxy-2-methyloctadecane as asex pheromone of the gypsy moth (Lymantria dispar),Z-13-hexadecen-11-ynyl acetate as a sex pheromone of the pineprocessionary moth, Z-7,15-hexadecadien-4-olide as a sex pheromone ofthe yellowish elongate chafer (Heptophylla picea), n-dodecyl acetate asa sex pheromone of the sugarcane wireworm (Melanotus okinawensis),E-9,11-dodecadienyl butyrate and E-9,11-dodecadienyl hexanate as sexpheromones of the sugarcane wireworm (Melanotus sakishimensis),(R)—Z-5-(oct-1-enyl)-oxacyclopentan-2-one as a sex pheromone of thecupreous chafer (Anomala cuprea), hexyl hexanoate, E-2-hexenyl hexanoateand octyl butyrate as sex pheromones of the rice leaf bug (Trigonotyluscaelestialium), hexyl butyrate, E-2-hexenyl butyrate andE-4-oxo-2-hexenal as sex pheromones of the sorghum plant bug (Stenotusrubrovittatus), (6R)—Z-3,9-dimethyl-6-isopropenyl-3,9-decadienylpropionate and (6R)—Z-3,9-dimethyl-6-isopropenyl-3,9-decadienol as sexpheromones of the white peach scale (Pseudaulacaspis pentagona),(S)-5-methyl-2-(1-propen-2-yl)-4-hexenyl 3-methyl-2-butenoate as a sexpheromone of the vine mealybug (Planococcus ficus), Z-9-tricosene as asex pheromone of the housefly (Musca domestica), gentisyl quinoneisovalerate as a sex pheromone of the German cockroach (Blattellagermanica), and 1,7-dioxaspiro[5.5]undecane as a sex pheromone of theolive fruit fly (Bactrocera oleae).

Additional examples of the pheromone used in the invention include,other than the above exemplified substances, a linear aliphatic aldehydehaving 12 to 20 carbon atoms, a linear aliphatic acetate being saturatedor having at least one double bond and having 12 to 20 carbon atoms, alinear aliphatic alcohol having 7 to 20 carbon atoms, a spiroacetalhaving 7 to 15 carbon atoms, a linear aliphatic ketone having 10 to 25carbon atoms, an aliphatic hydrocarbon having 10 to 30 carbon atoms, anda carboxylic acid having 10 to 20 carbon atoms.

Specific examples of the linear aliphatic aldehyde having 10 to 20carbon atoms include Z-5-decenal, 10-undecenal, n-dodecanal,Z-9-dodecenal, E5Z10-dodecadienal, ESE 10-dodecadienal, n-tetradecanal,Z7-tetradecenal, Z9-tetradecenal, Z11-tetradecenal,Z9E11-tetradecadienal, Z9Z11-tetradecadienal, Z9E12-tetradecadienal,Z9E11,13-tetradecatrienal, Z10-pentadecenal, E9Z11-pentadecadienal,n-hexadecanal, Z7-hexadecenal, E6Z11-hexadecadienal,E4Z6-hexadecadienal, E4E6Z11-hexadecatrienal, E10E12E14-hexadecatrienal,n-octadecanal, Z9-octadecenal, E14-octadecenal, E2Z13-octadecadienal,Z3Z13-octadecadienal, Z9Z12-octadecadienal, andZ9Z12Z15-octadecatrienal.

Specific examples of the linear aliphatic acetate being saturated orhaving one double bond and having 12 to 20 carbon atoms include decylacetate, Z3-decenyl acetate, Z4-decenyl acetate, undecyl acetate,Z7-undecenyl acetate, Z8-undecenyl acetate, E9-undecenyl acetate,dodecyl acetate, E7-dodecenyl acetate, Z7-dodecenyl acetate,E8-dodecenyl acetate, E9-dodecenyl acetate, 11-dodecenyl acetate,10-methyldodecenyl acetate, tridecyl acetate, Z4-tridecenyl acetate,E6-tridecenyl acetate, E8-tridecenyl acetate, Z8-tridecenyl acetate,tetradecyl acetate, Z7-tetradecenyl acetate, E8-tetradecenyl acetate,Z8-tetradecenyl acetate, E9-tetradecenyl acetate, Z9-tetradecenylacetate, E10-tetradecenyl acetate, Z10-tetradecenyl acetate,E12-tetradecenyl acetate, Z12-tetradecenyl acetate,12-methyltetradecenyl acetate, pentadecyl acetate, Z8-pentadecenylacetate, E9-pentadecenyl acetate, hexadecyl acetate, Z3-hexadecenylacetate, Z5-hexadecenyl acetate, E6-hexadecenyl acetate, Z7-hexadecenylacetate, Z9-hexadecenyl acetate, Z10-hexadecenyl acetate,Z12-hexadecenyl acetate, heptadecyl acetate, Z11-heptadecenyl acetate,octadecyl acetate, E2-octadecenyl acetate, Z11-octadecenyl acetate, andE13-octadecenyl acetate.

Specific examples of the linear aliphatic acetate having two or moredouble bonds and having 12 to 20 carbon atoms include an acetatecompound of a conjugated diene and/or a 1,4-pentadiene, such asZ3E5-decadienyl acetate, Z3E5-dodecadienyl acetate, E3Z5-dodecadienylacetate, E4Z10-dodecadienyl acetate, Z5E7-dodecadienyl acetate,E5Z7-dodecadienyl acetate, Z8Z10-dodecadienyl acetate, 9,11-dodecadienylacetate, E4Z7-tridecadienyl acetate, 11-methyl-Z9,12-tridecadienylacetate, E3E5-tetradecadienyl acetate, E8E10-tetradecadienyl acetate,Z10Z12-tetradecadienyl acetate, Z10E12-tetradecadienyl acetate,E10Z12-tetradecadienyl acetate, E10E12-tetradecadienyl acetate,E11,13-tetradecadienyl acetate, Z8Z10-pentadecadienyl acetate,Z8E10-pentadecadienyl acetate, Z8Z10-hexadecadienyl acetate,Z10E12-hexadecadienyl acetate, Z11Z13-hexadecadienyl acetate,Z11E13-hexadecadienyl acetate, E11Z13-hexadecadienyl acetate, andZ11E14-hexadecadienyl acetate.

Specific examples of the linear aliphatic alcohol having 7 to 20 carbonatoms include a saturated linear aliphatic alcohol and a linearaliphatic alcohol having at least one double bond, such as n-heptanol,Z4-heptenol, Z6-nonenol, Z6,8-nonadienol, E6,8-nonadienol, n-decanol,Z5-decenol, E5-decenol, n-undecanol, undecenol,11-chloro-E8E10-undecadienol, n-dodecanol, Z5-dodecenol, Z7-dodecenol,E7-dodecenol, Z8-dodecenol, E8-dodecenol, Z9-dodecenol, E9-dodecenol,E10-dodecenol, 11-dodecenol, Z5E7-dodecadienol, E5Z7-dodecadienol,E5E7-dodecadienol, Z7Z9-dodecadienol, Z7E9-dodecadienol,E7Z9-dodecadienol, 8,9-difluoro-E8E10-dodecadienol,10,11-difluoro-E8E10-dodecadienol,8,9,10,11-tetrafluoro-E8E10-dodecadienol, Z9,11-dodecadienol,E9,11-dodecadienol, n-tridecanol, n-tetradecanol, Z5-tetradecenol,E5-tetradecenol, Z7-tetradecenol, Z8-tetradecenol, Z11-tetradecenol,E11-tetradecenol, Z9Z11-tetradecadienol, Z9E11-tetradecadienol,Z9Z12-tetradecadienol, Z9E12-tetradecadienol, Z10Z12-tetradecadienol,E10E12-tetradecadienol, n-pentadecanol,6,10,14-trimethyl-2-pentadecanol, n-hexadecanol, Z9-hexadecenol,Z11-hexadecenol, E11-hexadecenol, Z7Z11-hexadecadienol,Z7E11-hexadecadienol, E10Z12-hexadecadienol, E10E12-hexadecadienol,Z11Z13-hexadecadienol, Z11E13-hexadecadienol, E11Z13-hexadecadienol,E11Z13-hexadecadienol, E4Z6Z10-hexadecatrienol, E4E6Z10-hexadecatrienol,n-octadecanol, Z13-octadecenol, E2Z13-octadecadienol,Z3Z13-octadecadienol, E3Z13-octadecadienol, and n-eicosanol.

Specific examples of the spiroacetal having 7 to 15 carbon atoms include1,6-dioxaspiro[4.5]decane, 2-ethyl-1,6-dioxaspiro[4.4]nonane,3-hydroxy-1,7-dioxaspiro[5.5]undecane,4-hydroxy-1,7-dioxaspiro[5.5]undecane,7-methyl-1,6-dioxaspiro[4.5]decane, 2-methyl-1,6-dioxaspiro[4.5]decane,2,7-dimethyl-1,6-dioxaspiro[4.4]nonane,2,4,8-trimethyl-1,7-dioxaspiro[5.5]undecane,2-methyl-1,7-dioxaspiro[5.5]undecane, 1,7-dioxaspiro[5.6]dodecane,2,8-dimethyl-1,7-dioxaspiro[5.5]undecane,2,2,8-trimethyl-1,7-dioxaspiro[5.5]undecane,2-ethyl-1,7-dioxaspiro[5.5]undecane,2-methyl-1,7-dioxaspiro[5.6]dodecane,2-ethyl-7-methyl-1,6-dioxaspiro[5.6]decane,7-ethyl-2-methyl-1,6-dioxaspiro[5.6]decane,2,7-diethyl-1,6-dioxaspiro[4.4]nonane,2,7-dimethyl-1,6-dioxaspiro[4.6]undecane,2-methyl-7-propyl-1,6-dioxaspiro[4.4]nonane,3-hydroxy-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane,2-propyl-1,7-dioxaspiro[5.5]undecane,2-ethyl-8-methyl-1,7-dioxaspiro[5.5]undecane,8-ethyl-2-methyl-1,7-dioxaspiro[5.5]undecane,2,7-diethyl-1,6-dioxaspiro[4.5]decane,2,7-dipropyl-1,6-dioxaspiro[4.4]nonane,7-butyl-2-methyl-1,6-dioxaspiro[4.5]decane,8-methyl-2-propyl-1,7-dioxaspiro[5.5]undecane, and2-propyl-8-methyl-1,7-dioxaspiro[5.5]undecane.

Specific examples of the linear aliphatic ketone having 10 to 25 carbonatoms include heptadecan-2-one, Z12-nonadecen-9-one,Z6Z9-nonadecadien-3-one, Z13-icosen-10-one, Z6-heneicosen-11-one,Z6-heneicosen-9-one, Z6E8-heneicosadien-11-one,Z6E9-heneicosadien-11-one, Z6Z9-heneicosadien-11-one, andZ7-tricosen-11-one.

Specific examples of the aliphatic hydrocarbon having 10 to 30 carbonatoms include 1E11-pentadecadiene, 1Z11-pentadecadiene,5,9-dimethylpentadecane, 2-methylhexadecane, 3,13-dimethylhexadecane,5,9-dimethylhexadecane, n-heptadecane, 2-methylheptadecane,2,5-dimethylheptadecane, 5-methylheptadecane, 5,11-dimethylheptadecane,7-methylheptadecane, 7,11-dimethylheptadecane, Z3Z6Z9-heptadecatriene,Z6Z9-heptadecadiene, Z7-octadecene, 10,14-dimethyl-1-octadecene,5,9-dimethyloctadecane, 2-methyloctadecane, 14-methyloctadecane,Z3Z6Z9-octadecatriene, n-nonadecane, 2-methylnonadecane,9-methylnonadecane, Z3Z6Z9Z11-nonadecatetraene,1E3Z6Z9-nonadecatetraene, Z3Z6Z9-nonadecatriene, Z6Z9-nonadecadiene,Z9-nonadecene, n-eicosane, Z9-eicosene, Z3Z6-eicosadiene,Z3Z6Z9-eicosatriene, 1Z3Z6Z9-eicosatetraene, 1Z3Z6Z9-heneicosatetraene,n-heneicosane, Z3Z6-heneicosadiene, Z6Z9-heneicosadiene,Z6Z9,20-heneicosatriene, Z3Z6Z9-heneicosatriene,Z6-13-methylheneicosene, Z9-heneicosene, n-docosene,Z3Z6Z9-docosatriene, Z6Z9-docosadiene, n-tricosane, Z7-tricosene,Z3Z6Z9-tricosatriene, Z6Z9-tricosadiene, n-tetracosane, n-pentacosane,Z3Z6Z9-pentacosatriene, n-hexacosane, n-heptacosane, n-octacosane, andn-nonacosane.

The carboxylic acid having 10 to 20 carbon atoms may be any compoundshaving a carboxyl group, and specific examples thereof include acarboxylic acid having two or more of methyl groups in the carbonskeleton thereof or having a double bond, such as 3,5-dimethyldodecanoicacid, Z-5-undecenoic acid, E-5-undecenoic acid, and(E,Z)-3,5-tetradecadienoic acid.

Specific examples of the attractant include an aliphatic carboxylic acidsuch as formic acid, acetic acid, propionic acid, n-butyric acid,isobutyric acid, n-valeric acid, isovaleric acid, caproic acid,isocaproic acid, E2-butenoic acid, 2-hydroxypropionic acid and malonicacid; an aliphatic aldehyde such as acetaldehyde, propanal, pentanal andE2-hexenal; an aliphatic ketone such as 2-butanone, pentane-2,4-dioneand cyclohexanone; an aliphatic carboxylic acid ester such as ethyllactate, ethyl acetate, isoamyl acetate, Z3-hexenyl acetate, decylacetate, hexyl 2-methylbutyrate, butyl hexanoate, ethyl octanoate, ethylnonanoate, ethyl decanoate, ethyl undecanoate, ethyl dodecanoate, ethylmyristate, ethyl palmitate, ethyl E2Z4-decadienoate, tert-butyl2-methyl-4-cyclohexenecarboxylate and tert-butyl 4(or5)-chloro-2-methyl-cyclohexanecarboxylate; an aliphatic alcohol such asethanol, isobutyl alcohol, isopentyl alcohol, 2-ethylhexanol,Z3-hexenol, 1-octen-3-ol, nonanol, decanol, cyclohexanol, acetoin andpropane 1,2-dial; an aliphatic ether such as diethyl ether and acetal;an aliphatic hydrocarbon such as α,β-ionone, undecane, tridecane,hexadecane, heptadecane and Z9-tricosene; an aromatic compound such asmethyl phenylacetate, ethyl phenylacetate, propyl phenylacetate,phenethyl phenylacetate, Z3-hexenyl benzoate, eugenol, methylisoeugenol, methyl eugenol, veratrole, 2-allyloxy-3-ethoxybenzaldehyde,4-(p-acetoxyphenyl)-2-butanone, 4-(p-hydroxyphenyl)-2-butanone(raspberry ketone), anisylacetone, methyl anthranilate, ethylanthranilate, benzyl salicylate, methyl salicylate, phenethyl alcohol,phenethyl propionate, phenethyl butyrate, anethole, vanillin, ethylvanillin, isovanillin, heliotropin, piperonal acetone and phthiocol; aheterocyclic compound such as maltol, ethyl maltol,2,5-dimethylpyrazine, γ-(4-pentenyl)-γ-butyrolactone, δ-nonyllactone andfrontalin; a sulfur-containing compound such as dimethyl disulfide,dimethyl trisulfide, dipropyl disulfide, methyl isothiocyanate and3-butenyl isothiocyanate; a nitrogen-containing compound such astrimethylamine, hexylamine, 4-diaminobutane, allylnitrile and methyl2-amino-3-methylvalerate; and a terpene compound such as geraniol,farnesol, linalool, linalool oxide, citronellol, cineol, geranylacetate, citronellyl acetate, citral, carvone, d-limonene, β-pinene,farnesene and 4,8-dimethyl-1,E3,7-nonatriene.

Other specific examples of the attractant include an essential oil suchas an angelica oil, a citronella oil and a mustard oil; and an extractfrom a plant such as aloe and eucalyptus.

Specific examples of the repellent include an aliphatic carboxylic acidsuch as Z9Z12-octadienoic acid and 3,7,11-trimethyl-6,10-dodecadienoicacid; an aliphatic aldehyde such as E2-hexenal,Z2E6-3,7-dimethyloctadienal, 3,7-dimethyl-6-octenal and E2Z6-nonadienal;an aliphatic ketone such as 2-heptanone, 2-dodecanone, 2-tridecanone,3-methyl-2-cyclohexenone, E3E5-octadien-2-one and E3Z7-decadien-2-one;an aliphatic carboxylic acid ester such as butyl acetate, octyl acetate,methyl myristate, methyl palmitate and methyl6-n-pentylcyclohexene-1-carboxylate; an aliphatic alcohol such asoctanol, 1-octen-3-ol, 2-ethyl-1,3-hexanediol, menthol andn-hexyltriethylene glycol monoether; an aliphatic hydrocarbon such astridecane; an aromatic compound such as cinnamic alcohol, cinnamicaldehyde, methyleugenol, phenylacetaldehyde, benzaldehyde, anethole,diethyltoluamide, N,N-diethyl-3-methylbenzamide (DEET), dimethylphthalate, dioctyl phthalate and naphthalene; a heterocyclic compoundsuch as γ-nonyllactone, butyl3,4-dihydro-2,2-dimethyl-4-oxo-2H-pyran-6-carboxylate, furfural and4-octanoylmorpholine; a sulfur-containing compound such as propylisothiocyanate; a nitrogen-containing compound such as methylpiperidine,2,6-dimethylpiperidine and 2-ethylpiperidine; and a terpene compoundsuch as geraniol, cineole, linalool, terpineol, citral, citronellal,neryl formate, a-pinene, carvone, d-limonene and camphor.

Additional examples may include an essential oil such as a rose geraniumoil, a sandalwood oil, a pepper oil (peppermint oil) and a lemongrassoil; and an extract from a plant such as cinnamon, camphor, clover,thyme, geranium, bergamot, laurel, pine, Betula lenta, pennyroyal,eucalyptus and margosa.

Moreover, a pyrethroid compound such as pyrethrin, allethrin,phthalthrin, resmethrin, flumethrin, phenothrin, permethrin,cyphenothrin, prallethrin, etofenprox, empenthrin and transfluthrin mayalso be used.

EXAMPLES Example 1

As described below, there is provided a high-density polyethylene tubecontaining Z-11-tetradecenyl acetate, which is a sex pheromone of theleaf roller, and having an inner diameter of 1.0 mm and a wall thicknessof 0.40 mm, wherein the tube is sealed at intervals of 200 mm and usedfor sustained-release sex pheromone preparations.

By using an extruder with a crosshead and a die, a tube was extrudedfrom the die at 250° C. The extruded tube was taken up by take-uprollers at a speed of 80 m/min. Although the tube becomes thinner bytake-up from the discharge port, the tube was continuously taken up at aconstant speed to control the amount of the extruded polymer material sothat the outer diameter and the wall thickness of the tube wereadjusted. In a pore provided in a mandrel inserted into the die, aconduit communicating with the outside and being switchable to injectair or a liquid was provided. By controlling the amount of air fed intothe conduit, the inner diameter of a tube was adjusted. The dimensionsof an intended tube were selected by controlling the take-up speed, theextruded amount of polymer material and the amount of air, and then theconduit was switched to feed a liquid substance at a flow rate of 62.8g/min which corresponded to the inner diameter of the polymer tube toobtain a long polymer tube containing the liquid substance thereinconcurrently with the extrusion. The flow rate of the liquid substancewas able to be calculated in accordance with πr²dv wherein r is theradius of an inner diameter, π is the circle ratio, d is the density ofa liquid, and v is a take-up speed.

As a device for pressure-bonding the polymer tube extruded from thedischarge port before introduction into a cooling bath forsolidification, two rotary horns having respective protrusions (eachhorn having one protrusion) were placed between the discharge port ofthe die and a water bath, so that the protrusions came into contact withand pressed the polymer tube to cause pressure-bonding. Each rotary hornwith the protrusion was a cylindrical rotary horn having a radius(including the protrusion) of 31.85 mm. Accordingly, each rotary hornhad an outer periphery of 200 mm. The two protrusions come into contactwith and pressure-bond a polymer tube, but if the protrusions come intocontact with each other, the polymer tube is cut. Hence, the two rotaryhorns were placed away from each other to make a clearance of 0.5 mm sothat the polymer tube having an outer diameter 1.8 mm was flattened to0.5 mm. Each rotary horn was rotated at a speed of 400 rpm so that theperipheral speed of each protrusion was the same as the take-up speed of80 m/min. The speed of a rotary motor for the take-up rollers wasmeasured, and electric signals were sent to a rotary motor controller ofthe rotary horns for pressure-bonding, thereby controlling theperipheral speed of the rotary horns for pressure-bonding. Thus, evenwhen there is a change in the rotation speed of the rotary motor for thetake-up rollers, for example, owing to a change in voltage, theperipheral speeds of the rotary horns for pressure-bonding werecontrolled so that constant sealing pitches were able to be maintained.

Example 2

As described below, there are provided two ethylene-vinyl acetatecopolymer (having vinyl acetate content of 4% by mole) tubes, each tubecontaining therein E8E10-dodecadienol, which is a sex pheromone ofcodling moth, and having an inner diameter of 1.2 mm and a wallthickness of 0.50 mm, wherein the two horizontally aligned tubes aresealed and thereby connected horizontally at intervals of 200 mm and areused for sustained-release sex pheromone preparations.

By using an extruder with a crosshead and a die, two tubes were extrudedfrom the die at 175° C. The extruded tubes were taken up by take-uprollers at a speed of 60 m/min. Although the tubes become thinner bytake-up from the discharge ports, the tubes were continuously taken upat a constant speed to control the amount of the extruded polymermaterial so that the outer diameter and the wall thickness of each tubewere adjusted. In a pore provided in each of two mandrels inserted intothe die, a conduit communicating with the outside and switchable toinject air or a liquid was provided. By controlling the amount of airfed into the conduit, the inner diameter of each tube was adjusted. Thedimensions of each intended tube were selected by the controlling thetake-up speed, the extruded amount of polymer material and the amount ofair, and then the conduit was switched to feed a liquid substance at aflow rate of 59.7 g/min which corresponded to the inner diameter of eachpolymer tube to obtain two long polymer tubes containing the liquidsubstance therein concurrently with extrusion. The flow rate of theliquid substance was able to be calculated in accordance with πr²dvmentioned above.

As a device for pressure-bonding the polymer tubes extruded from thedischarge ports before introduction into a cooling bath forsolidification, two rotary horns having respective protrusions (eachhorn having one protrusion) were placed in a first water bath which wasplaced next to the discharge ports of the die and which was controlledto have a water bath temperature of 80° C., so that the protrusions cameinto contact with and pressed the polymer tubes to causepressure-bonding. Each rotary horn with the protrusion was a cylindricalrotary horn having a radius (including the protrusion) of 63.7 mm.Accordingly, each rotary horn had an outer periphery of 400 mm. The twoprotrusions come into contact with and pressure-bond polymer tubes, butif the protrusions come into contact with each other, the polymer tubesare cut. Hence, the two rotary horns were placed away from each other tomake a clearance of 0.7 mm so that the two polymer tubes, each tubehaving an outer diameter of 2.2 mm, were flattened to 0.7 mm. Eachrotary horn was rotated at a speed of 300 rpm so that the peripheralspeed of each protrusion was the same as the take-up speed of 60 m/min.The speed of a rotary motor for the take-up rollers was measured, andelectric signals were sent to a rotary motor controller of the rotaryhorns for pressure-bonding, thereby controlling the peripheral speed ofthe rotary horns for pressure-bonding. Thus, even when there is a changein the rotation speed of the rotary motor for the take-up rollers, forexample, owing to a change in voltage, the peripheral speeds of therotary horns for pressure-bonding were controlled so that constantsealing pitches were able to be maintained.

Example 3

As described below, there are provided two tubes connected by a web,each tube containing therein a mixture of Z-11-hexadecenyl acetate andZ-11-hexadecenal at weight ratio of 1:1, which are sex pheromonesubstances of diamondback moth, being made from a copolymer ofpolybutylene succinate and polybutylene adipate (trade name: Bionolle#3010, product of Showa Highpolymer Co., Ltd.) and having an innerdiameter of 1.04 mm and a wall thickness of 0.35 mm, wherein the twohorizontally aligned tubes are horizontally pressed for sealing atintervals of 1,000 mm and are used for sustained-release sex pheromonepreparations.

By using an extruder with a crosshead and a die, two tubes connected bya web were extruded from the die at 140° C. The width of a slit in a die(the minimum distance between the outer peripheries of pores in a die)was 3.5 mm and the thickness of the slit, which was perpendicular to thewidth, was 0.20 mm. The extruded tubes were taken up by taken-up rollersat a speed of 50 m/min. Although the tubes become thinner by being takenup from the discharge ports, the tubes were continuously taken up at aconstant speed to control the amount of the extruded polymer material sothat the outer diameter and the wall thickness of each tube wereadjusted. In a pore provided in each of two mandrels inserted into thedie, a conduit communicating with the outside and switchable to injectair or a liquid was provided. By controlling the amount of air fed intothe conduit, the inner diameters of each tube was adjusted. Thedimensions of each intended tube were selected by controlling thetake-up speed, the extruded amount of polymer material and the amount ofair, and then the conduit was switched to feed a liquid substance at aflow rate of 37.4 g/min which corresponded to the inner diameter of eachpolymer tube to obtain two long polymer tubes containing the liquidsubstance therein concurrently with extrusion. The flow rate of theliquid substance was able to be calculated in accordance with πr²dvmentioned above.

As a device for pressure-bonding the polymer tubes extruded from thedischarge ports before introduction into a cooling bath forsolidification, two rotary horns having respective protrusions (eachhorn having one protrusion) were placed in a first water bath which wasplaced next to the discharge ports of the die and which was controlledto have a water bath temperature of 60° C., so that the protrusions cameinto contact with and pressed the polymer tubes to causepressure-bonding. Each rotary horn with the protrusion was a cylindricalrotary horn having a radius (including the protrusion) of 31.85 mm.Accordingly, each rotary horn had an outer periphery of 200 mm. The twoprotrusions come into contact with and pressure-bond polymer tubes, butif the protrusions come into contact with each other, the polymer tubesare cut. Hence, the two rotary horns were placed away from each other tomake a clearance of 0.5 mm so that the two polymer tubes, each tubehaving an outer diameter of 1.74 mm, were flattened to 0.5 mm. The twohorizontally aligned polymer tubes connected by a web were taken upbetween two rotary horns so that the two polymer tubes were pressedhorizontally by the protrusions. The rotating speed of the rotary hornscorresponded to the take-up speed of 50 m/min, and the rotary horns werestopped for 0.96 seconds and then rotated once for 0.24 seconds. Thiscycle was repeated to achieve the sealing at each pitch of 1,000 mm. Thespeed of a rotary motor for the take-up rollers was measured, andelectric signals were sent to a rotary motor controller of the rotaryhorns for pressure bonding, thereby controlling the peripheral speed ofthe rotary horns for pressure-bonding. Thus, even when there is a changein the rotation speed of the rotary motor for the take-up rollers, forexample, owing to a change in voltage, the peripheral speeds of therotary horns for pressure-bonding were controlled so that constantsealing pitches were able to be maintained.

Example 4

As described below, there are provided two high-density polyethylenetubes connected by a notched web, each tube containingE,Z-7,9-dodecadienyl acetate, which is a sex pheromone of the Europeangrape vine moth, and having an inner diameter of 1.40 mm and a wallthickness of 0.40 mm, wherein the two vertically aligned tubes arehorizontally pressed for sealing at intervals of 200 mm and are used forannular sustained-release sex pheromone preparations.

By using an extruder with a crosshead and a die, two tubes connected bya web were extruded from the die at 280° C. The width of a slit in a die(the minimum distance between the outer peripheries of pores in a die)was 4.5 mm and the thickness of the slit, which was perpendicular to thewidth, was 0.10 mm. The extruded tubes were taken up by take-up rollersat a speed of 50 m/min. Although the tubes become thinner by being takenup from the discharge ports, the tubes were continuously taken up at aconstant speed to control the amount of the extruded polymer material sothat the outer diameter and the wall thickness of each tube wereadjusted. In a pore provided in each of two mandrels inserted into thedie, a conduit communicating with the outside and switchable to injectair or a liquid was provided. By controlling the amount of air fed intothe conduit, the inner diameters of each tube was adjusted. Thedimensions of each intended tube were selected by controlling thetake-up speed, the extruded amount of polymer material and the amount ofair, and then the conduit was switched to feed a liquid substance at aflow rate of 67.7 g/min which corresponded to the inner diameter of eachpolymer tube to obtain two long polymer tubes containing the liquidsubstance therein concurrently with extrusion. The flow rate of theliquid substance was able to be calculated in accordance with πr²dvmentioned above.

As a device for pressure-bonding the polymer tubes extruded from thedischarge ports before introduction into a cooling bath forsolidification, two rotary horns having protrusions (each horn havingone protrusion) were placed in a first water bath which was placed nextto the discharge ports of the die and which was controlled to have awater bath temperature of 30° C., so that the protrusions came intocontact with and pressed the tubes to cause pressure-bonding. One rotaryhorn had a blade which was located at 5 mm apart from each side of theprotrusion and at the corresponding location for cutting the web, whilethe other rotary horn had a blade receiver with a groove, the receiverprotruding radially and being located at 5 mm apart from each side ofthe protrusion. Each rotary horn with the protrusion was a cylindricalrotary horn having a radius (including the protrusion) of 31.85 mm.Accordingly, each rotary horn had an outer periphery of 200 mm. The twoprotrusions come into contact with and pressure-bond polymer tubes, butif the protrusions come into contact with each other, the tubes are cut.Hence, the two rotary horns were placed away from each other to make aclearance of 0.6 mm so that the two tubes, each tube having an outerdiameter of 2.2 mm, were flattened to 0.6 mm. The two tubes were takenup so as to allow the two vertically aligned tubes to be pressed in thehorizontal direction between the two rotary horns. The rotary horns wererotated at a speed of 250 rpm so that the peripheral speed of theprotrusions was the same as the take-up speed of 50 m/min. When the twotubes with web were being taken up, the rotary horns were rotated sothat the blade came into contact with the web and the groove, therebynotching the web. The speed of a rotary motor for the take-up rollerswas measured, and electric signals were sent to a rotary motorcontroller of the rotary horns for pressure-bonding. Thus, even whenthere is a change in the rotation speed of the rotary motor for thetake-up rollers, for example, owing to a change in voltage, theperipheral speeds of the rotary horns for pressure-bonding werecontrolled so that constant sealing pitches were able to be maintained.

1. A method for producing a polymer tube, containing a liquid thereinand being sealed at constant intervals, the method comprising: anextrusion step of continuously melt-extruding a polymer material througha die into at least one tube, while feeding a liquid into the at leastone tube to obtain at least one liquid-containing tube; and a sealingstep of discontinuously pressing the at least one liquid-containing tubebetween a pair of pressurizing members at constant intervals to causepressure-bonding before the tube solidifies, while continuously takingup the extruded tube.
 2. The method according to claim 1, wherein thepair of pressurizing members is a pair of rotary horns, each horn havinga protrusion, and in the sealing step, the at least oneliquid-containing tube is discontinuously pressed between theprotrusions of the rotary horns which rotate at a peripheral speed equalto a constant speed of taking up the extruded tube to transfer thediscontinuously pressed tube in a direction of taking up the extrudedtube.
 3. The method according to claim 1 or claim 2, wherein the atleast one tube is two tubes and in the sealing step, the twoliquid-containing tubes are discontinuously pressed to causepressure-bonding for sealing and thereby simultaneously connecting thetwo liquid-containing tubes with each other.
 4. The method according toclaim 1 or claim 2, wherein the at least one tube is two tubes connectedby an interconnecting web and in the sealing step.
 5. The methodaccording to claim 2, wherein the at least one tube is two tubesconnected by an interconnecting web whose faces oppose to the rotaryhorns; one of the rotary horns has a blade which protrudes radiallyhigher than the protrusion on the circumference and in the sealing step,the blade cut the web to form notches in a longitudinal direction exceptat locations where the two tubes are pressed, keeping the twoliquid-containing tubes connected by the web having the notches.
 6. Anapparatus for producing a polymer tube, containing a liquid therein andbeing sealed at constant intervals, the apparatus comprising: a dieconfigured for melt extrusion of a polymer material into at least onetube; a mandrel configured to feed a liquid into the at least one tubeduring the melt extrusion to obtain at least one liquid-containing tube;one or more rollers configured to take up the at least oneliquid-containing tube; and a pair of pressurizing members configured todiscontinuously press the at least one liquid-containing tube betweenthe pair of pressurizing members to cause pressure-bonding before thetube solidifies.
 7. The apparatus according to claim 6, wherein the pairof pressurizing members is a pair of rotary horns, each horn having aprotrusion, and the pair of rotary horns is configured todiscontinuously press the at least one liquid-containing tube betweenthe protrusions to cause pressure-bonding.
 8. The apparatus according toclaim 7, wherein the die comprises two discharge pores and a slitconnecting the two discharge ports, and one of the rotary horns has ablade which protrudes radially higher than the protrusion on thecircumference.
 9. The apparatus according to claim 7, comprising a guideconfigured to support the at least one liquid-containing tube and placedaround the protrusion of one of the rotary horns.
 10. The apparatusaccording to any one of claims 6 to 9, further comprising a cooling bathconfigured to cool the discontinuously pressed tube.